Lighting apparatus for a museum display case

ABSTRACT

A support grid, formed as a grid including a number of longitudinal support rods and a number of transverse support rods, is used to support a number of lighting fixtures, each of which projects light emitted from an end of a fiber optic tail. The fiber optic tails are joined into a fiber optic bundle illuminated by a light source. The support grid allows placement of the fixtures to be located in the longitudinal and transverse directions to light various objects within chamber of a museum display case, while the light source is held outside the chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to illuminating objects within a display case, and, more particularly, to providing illumination for viewing valuable and easily damaged objects within a museum display case in a manner providing flexibility to establish and modify complex patterns of illumination.

2. Summary of the Background Art

Museums typically need to place a number of artifacts that are valuable and easily damaged on public display. Such artifacts include archeological treasures, ancient manuscripts, and the like, which include materials and pigments that are easily damaged by exposure to air, moisture, heat, certain forms of energy, such as UV (ultraviolet) energy, and various pollutants. Efforts to protect such artifacts while providing for their display have been centered on the development of air tight display cases with transparent windows, and with appropriate means for conditioning and maintaining the air inside the cases to minimize damage to the artifacts. The objects within such display cases were conventionally illuminated only with light entering the case from outside, so that the heat generated by lamps would not affect the objects, and so that the frequencies of radiant energy striking the objects would be limited to those frequencies readily transmitted though glass, reducing the effects of UV energy. For example, such illumination can come from spotlights mounted on the walls or in the ceiling of the building, or from recessed lighting fixtures, including lighting from fluorescent strips.

An example of such a display case is described in U.S. Pat. No. 4,749,241 as a display case for supporting and viewing a museum piece, with the case including a base providing a lower chamber for a humidity buffer and a transparent cover providing an upper chamber for the piece on display. The case is substantially airtight, with sealed access ports in the base for inserting and removing humidity buffer containers, and with a clamped soft seal between the cover and the base, providing for the removal of the cover from the base to provide access to the display space.

Another example of such a display case is described in U.S. Pat. No. 5,127,718 as a sealed display and storage case for viewing and storing a museum piece of the like in a protected and controlled environment. The display case includes a base having apertures therethrough, a top cover, and a bottom cover. A first seal mechanism attaches the top cover to the base, providing an upper microclimate chamber, and a second seal mechanism attaches the bottom cover to the base, providing a lower microclimate chamber. Apertures within the base limit air flow exchange between the upper and lower microclimate chambers, with a rotatable disc mechanism closing the apertures when either cover is removed for servicing to eliminate the flow of outside air into the unopened chamber.

Disadvantages of a reliance on the use of lighting outside the display case to illuminate objects inside the display case include the dominance of reflections on the glass surfaces of the case, an inability to illuminate individual objects within the display case or to enhance the display of individual objects through consideration of the dimensions, shapes, material or the conditions under which they are displayed, and difficulties in changing the illumination in an appropriate way when the objects within the case are changed.

Substantial improvements in the illumination of objects within museum display cases have been achieved through the use of fiber optic lighting, which allows the transmission of light from optical fibers and from fixtures including optical elements, such as lenses, within the display case, while providing for the generation of the light by lamps outside the display case. In this way, the heat produced by the lamps does not affect the objects .within the display case. Furthermore, the frequencies of light striking the objects within the display are limited to the frequencies transmitted by the optical fibers and by additional filtration, if desired.

The patent literature includes a number of descriptions of fiber optics track lighting or light bars, in which light generated within a light source is transmitted through a number of fiber optics bundles to fixtures emitting light, with the fixtures being aligned in various positions along the length of an elongated housing. For example, U.S. Pat. No. 5,050,047 describes a system of pinpoint lighting comprising a plurality of lens units supplied with light by the separated tail ends of a fiber optic cable of which the remote end is supplied by a simple light source. The lens units, which are carried by plastic extruded plates extending at various locations along the length of a plastic extruded trunking bar, provide separate beams of light which are directed at individual articles such as individual items of jewelry in a display case. Each lens unit is adjustable so that the direction and intensity of the light beam can be varied.

A fiber optics light bar is described in U.S. Pat. No. 5,000,535, as including an elongated metal channel having a U-shaped cross-section with a cover and end caps secured thereto to form a housing, with longitudinally spaced holes being drilled along one wall of the housing. Metal collars are fixed in some of the holes, which may have different orientations. In each of the collars, an end of one of a bundle of optical fibers is secured by an adhesive, with the end of the fiber being polished after the adhesive has been cured. The fibers are led through the housing to an opening at which a flexible sleeve is mounted. The fibers are threaded through the flexible sleeve and are secured in a tip at the other end of the sleeve, where the fibers are secured by an epoxy and polished.

Another fiber optics light bar is described in U.S. Pat. No. 5,999,686 as a hollow light bar housing a plurality of coiled fiber optics bundles, with a number of individual spot lights selectively spaced in a line along the light bar housing. Each spot light is formed by a bundle of fibers collected in a casing fitted with a rotatable ball held in placed within a locking cage.

Another form of fiber optic track lighting is described in U.S. Pat. No. 5,325,272 as comprising an elongated track channel having a generally U-shaped cross-section on a longitudinal axis, with legs descending from a base. Each of the legs includes an inward-facing longitudinal groove in which a number of luminaire holders are slidably engaged to hold a fiber optic luminaire to be positionable along the longitudinal axis of the channel. Fiber optic light guides receiving light from a remote source of illumination, extend within the channel to a light-emitting end. An optical element retained in each luminaire intercepts the emitted light, producing a substantially collimated light beam reflected from a mirror, which can preferably be adjusted by rotation about two axes to position a downward reflection of the beam through the open lower side of the channel.

Yet another form of fiber optic track lighting is described in U.S. Pat. No. 6,082,884, in the form of a channel including a number of subassemblies mounted within an elongated housing, with a fiber optic cable or light guide directing light at each of the subassemblies, and with each of the subassemblies including optical elements for focusing and directing the light.

Other patents describe individual lighting fixtures for producing adjustable patterns of illumination from fiber optic bundles. For example, U.S. Pat. No. 5,268,977 describes a luminaire including a tubular housing having composite macro lens on an optical axis at a distal end of the housing. A light emitter slidably disposed in a support tube at the proximal end of the housing is formed at an end of a fiber optic light guide having a remote end accepting light from a remote source. The composite macro lens forms a principal focus at a first focal plane to produce a narrow beam but additionally includes a plurality of contiguous micro lenses having a second focal plane axially displaced from the first focal plane. The luminaire is zoomed to produce a wider projected beam of uniform intensity by moving the light emitter along the optical axis.

U.S. Pat. No. 5,907,648 describes an aimable fiber-optic spotlight having a fiber-optic light guide with a first end receiving light from a remote light source and a second end emitting light at the focus of a beam forming lens held in a fixed tubular housing. The second end of the light guide is transversely adjustable relative to the optical axis of the lens to adjust the angle at which a light beam is projected.

What is needed is a support grid for holding fiber optic lighting fixtures in a manner allowing the to be easily positioned at various locations separated in a longitudinal direction along the length of a display case and in a transverse direction, from front to rear in a display case. Additionally, what is needed is such a support grid configured to allow easy changes in an illumination pattern produced by the fiber optic lighting fixtures when the objects being displayed in the display case are changed.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, a support grid is provided for supporting fiber optic lighting fixtures within a display case. The support grid includes a first plurality of longitudinal support rods, extending in a longitudinal direction, and a second plurality of transverse support rods, extending in a transverse direction. The transverse direction is perpendicular to the longitudinal direction.

The support grid may be composed of metal, with the longitudinal support rods being welded to the transverse support rods. Alternately, support grid may additionally include a number of coupling devices clamping the transverse support rods to the longitudinal support rods. The support grid may include a number of support grids supported by at least one intervening support beam. The support grid may be formed as a rectangular frame.

In accordance with another aspect of the invention, lighting apparatus is provided, with the lighting apparatus including the support grid, a light source, and a fiber optic bundle. The fiber optic bundle includes a first end illuminated by the light source and a plurality of tails. Each of the fixtures projects light from an end of a tail within the plurality of tails and includes a clamp holding the fixture to a support rod within the support grid.

In accordance with yet another aspect of the invention, a display cabinet is provided, with the display cabinet including a light chamber, a fiber optic bundle, and a display chamber. The light chamber holds a light source. The fiber optic bundle includes a first end illuminated by the light source and a plurality of tails. The display chamber holds the support grid and a plurality of the fixtures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of lighting apparatus built in accordance with the present invention;

FIG. 2 is a partly sectional elevation of the lighting apparatus of FIG. 1, showing the attachment of a fixture to a support grid therein;

FIG. 3 is a fragmentary cross-sectional side elevation of a display case including the lighting apparatus of FIG. 1;

FIG. 4 is an exploded perspective view of a coupling used to join rods within an alternative version of a support grid for the lighting apparatus of FIG. 1;

FIG. 5 is a perspective view of a support grid built in accordance with a first alternative embodiment of the present invention; and

FIG. 6 is a perspective view of lighting apparatus built in accordance with a second alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE DESCRIPTION

FIG. 1 is a perspective view of lighting apparatus 10 built in accordance with the present invention to include a support grid 12, to which a number of fiber optic fixtures 14 are attached by means of individual clamps 16. Each of the fixtures 14 is connected to an end of a fiber optic tail 18 through which light is provided to the fixture 14. The support grid 12 includes a number of longitudinal rods 20, extending in the longitudinal direction indicated by arrow 22, along the length of the support grid 12, and a number of transverse rods 24, extending in the transverse direction indicated by arrow 26, across the width of the support grid 12.

FIG. 2 is a partly sectional elevation of the lighting apparatus 10, showing the attachment of a fixture 14 to one of the rods 20 or 24 of the support grid 12. For example, each of the individual fixtures 14 includes one or more lenses 25 within a tubular housing 26, with the lens(es) 24 being configured to produce, from the light emitted by an end 28 of the fiber optic tail 18, a conically shaped light beam 30 emitting from the fixture 14. The clamp 16 of the fixture includes a threaded hole 32 engaging a setscrew 34 that is tightened to hold the fixture 14 in place on the rod 20 or 24.

Referring again to FIG. 1, the fixtures 14 also accept accessories to further modify the light beam, such as barn doors 36, and filter holders 38. The characteristics of the light beam projected from a fixture 14 can further be modified by a device attached to a separate support, such as an opaque flag 40 held by a flag support member 42, or a filter 44 held within a filter frame 46. An individual fixture 14 may be directly attached to a rod 20 or 24 of the support grid 12, or it may be attached to the support grid 12 by means of an attachment accessory rod 48 having a clamp 50 attached to the support grid 12 with a setscrew 52, so that additional flexibility is achieved in the angular positioning of the fixture 14 together with associated accessories, such as the flag support member 42 or the filter frame 46.

FIG. 3 is a fragmentary cross-sectional side elevation of a display case 60 including an example of the lighting apparatus 10, illuminating objects 62 within a display chamber 64 of the case 60. The display case 60 additionally includes a lighting chamber 66 holding an illuminator case 68, in which a light source 70 illuminates an end 72 of a fiber optic bundle 74, from which fiber optic tails 18 extend to various fixtures 14 within the lighting apparatus 10. The lighting chamber 66 is separated from the display chamber 64 by a ceiling 76 of the display chamber 64, which prevents the substantial transfer of heat from the illuminator case 68 into the display chamber 64. A lower chamber 78 of the display case 60 may include, for example, means for controlling the temperature and humidity of air within the display chamber 64. The display case 60 includes illumination support brackets 80 holding the support grid 12 within the illumination apparatus 10 in place below the ceiling 16.

Each of the fixtures 14 forms a cone of projected light to form a spot light, with a wide cone 82 being used to illuminate a large object 82, together with a background surface 86 disposed behind the object 82, with a narrow cone 88 being used to illuminate a smaller object 90, and with a pair of cones 92 being used to illuminate different portions of an object 94. This exemplary pattern of illumination is established by taking advantage of the ability of the support grid 12 to place lighting fixtures at various locations separated from one another in both the transverse direction indicated by arrow 25 and additionally in the longitudinal direction indicated by arrow 22 (shown in FIG. 1). Individual objects, and portions of individual objects, within the display chamber 64 are separately illuminated, without a need to similarly illuminate intervening surfaces within the chamber 64, and with the direction of lighting for each object being chosen to achieve a particular effect. With the use of filters 42, as shown in FIG. 1, the color of an individual light pattern can additionally be varied to achieve a desired effect.

In the example of FIG. 1, the support grid 12 is formed by a number of longitudinal rods 20, which are evenly spaced apart from one another, and a number of transverse rods 22, which are additionally evenly spaced apart from one another. For example, the rods 20, 22 may be composed of steel, being joined by projection welding and coated. Alternately, the rods 20, 22 may be joined by brazing, may be hollow, and may be composed of another metal, such as aluminum.

FIG. 4 is an exploded perspective view of a mechanical coupling 100 used to join longitudinal rods 102 and transverse rods 104 to form an alternative support grid 106. The coupling 100 includes a longitudinal rod clamping member 108 having a slot 110, in which the longitudinal rod 102 is held, and a transverse rod clamping member 112 having a slot 114, in which the transverse rod 104 is held. The rod clamping members 108, 112 are held together by a clamping screw 116 extending through a hole 118 in the transverse rod clamping member 112 to engage a threaded hole 120 in the longitudinal rod clamping member 108, with a clamping force being exerted to clamp the rods 104, 106 together. The clamping members 102, 108 are held in alignment with one another by pins 122 sliding in slots 124. The mechanical couplings 100 are placed at some or all of the intersections of longitudinal and transverse rods 102, 104 within the support grid 106, with the clamping screws 116 being loosened to allow movement of the rods 102, 104 and tightened to hole the rods 102, 104 in place. When compared to welding, the use of mechanical couplings has a disadvantage of increased complexity and generally of increased cost, but an advantage of flexibility, in that additional rods can be added, and the distances between adjacent rods can be changed as the requirements placed on an individual lighting apparatus change.

In either case, the rods within the support grid are preferably round, having a diameter of 5-13 mm. Within this range, the diameter of the rod is preferably 6 mm.

FIG. 5 is a perspective view of a support grid 130 built in accordance with a first alternative embodiment of the invention to include a number of individual support grids 132 supported by at least one intervening support beam 134. Such a configuration may be used to provide lighting for a particularly large display case.

FIG. 6 is a perspective view of a lighting apparatus 140 built in accordance with a second alternative embodiment of the invention to include a support grid 142 formed as a rectangular frame having two longitudinal rods 144 and two transverse rods 146. The support grid 142 may be formed as an integral structure by cutting and forming a steel rod into a rectangular shape and by but welding its ends together. The lighting apparatus 140 includes various fixtures 14, as described above in reference to FIGS. 1 and 2, connected to the ends of fiber optic tails 18, being attached to the support grid 142 by means of clamps 16, together with accessories for modifying light projected from the fixtures 14, such as barn doors 36, an opaque flag 40, and a filter 44 within a filter frame 46. Certain accessories, such as the barn doors 36, are connected to an associated fixture 14, while other accessories, such as the filter 44 within the filter frame 46 are connected to the support grid 142 by a separate clamp 148.

While the invention has been described in its preferred forms or embodiments with some degree of particularity, it is understood that this description has been given only by way of example, and that many variations can be made without departing from the spirit and scope of the invention, as defined in the appended claims. 

1. A support grid for supporting fiber optic lighting fixtures within a display case, wherein the support grid comprises a first plurality of longitudinal support rods extending in a longitudinal direction; and a second plurality of transverse support rods extending in a transverse direction, perpendicular to the longitudinal direction.
 2. The support grid of claim 1, composed of metal, wherein the longitudinal support rods are welded to the transverse support rods.
 3. The support grid of claim 1, additionally comprising a third plurality of coupling devices clamping the transverse support rods to the longitudinal support rods.
 4. The support grid of claim 1, comprising a plurality of support grids supported by at least one intervening support beam.
 5. The support grid of claim 1, wherein the support grid is formed as a rectangular frame.
 6. Lighting apparatus for a display case, wherein the lighting apparatus comprises: a support grid including a plurality of longitudinal support rods extending in a longitudinal direction and a plurality of transverse support rods extending in a transverse direction, perpendicular to the longitudinal direction; a light source; a fiber optic bundle including a first end illuminated by the light source and a plurality of tails; and a plurality of fixtures, wherein each of the fixtures projects light from an end of a tail within the plurality of tails, and wherein each of the fixtures includes a clamp holding the fixture to a support rod within the support grid.
 7. The lighting apparatus of claim 6, wherein the support grid is composed of metal, and the longitudinal support rods are welded to the transverse support rods.
 8. The lighting apparatus of claim 6, wherein the support grid additionally includes a third plurality of coupling devices clamping the transverse support rods to the longitudinal support rods.
 9. The lighting apparatus of claim 6, wherein the support grid includes a plurality of support grids supported by at least one intervening support beam.
 10. The lighting apparatus of claim 6, wherein the support grid is formed as a rectangular frame.
 11. The lighting apparatus of claim 6, additionally comprising accessories attached to the fixtures for modifying the light patterns projected from the fixtures.
 12. The lighting apparatus of claim 6, additionally comprising accessories attached to the support grid for modifying the light patterns projected from the fixtures.
 13. A display case comprising: a lighting chamber holding a light source; a fiber optic bundle including a first end illuminated by the light source and a plurality of tails; a display chamber holding a support grid and a plurality of fixtures, wherein the support grid includes a plurality of longitudinal support rods extending in a longitudinal direction and a plurality of transverse support rods extending in a transverse direction, perpendicular to the longitudinal direction; wherein each of the fixtures projects light from an end of a tail within the plurality of tails, and wherein each of the fixtures includes a clamp holding the fixture to a support rod within the support grid.
 14. The display case of claim 13, wherein the support grid is composed of metal, and the longitudinal support rods are welded to the transverse support rods.
 15. The display case of claim 13, wherein the support grid additionally includes a third plurality of coupling devices clamping the transverse support rods to the longitudinal support rods.
 16. The display case of claim 136, wherein the support grid includes a plurality of support grids supported by at least one intervening support beam.
 17. The display case of claim 13, wherein the support grid is formed as a rectangular frame.
 18. The display case of claim 13, additionally comprising accessories attached to the fixtures for modifying the light patterns projected from the fixtures.
 19. The display case of claim 13, additionally comprising accessories attached to the support grid for modifying the light patterns projected from the fixtures. 